1. Field of the Invention
The present invention relates generally to methods of accelerating and idling an internal combustion engine for an automotive vehicle. More particularly, the present invention relates to a method for accelerating and idling an internal combustion engine utilizing a dynamic fuel source.
2. Description of the Related Art
A problem with internal combustion engines arises when idling or a demand for acceleration is created by the operator of the motor vehicle and a fuel is used having a higher than normal distillation point. The fuel injection system will deliver fuel to the intake ports and the cylinders of the internal combustion engine a fixed volume of fuel. A fixed volume of fuel is delivered to each of the intake ports of the cylinders of the internal combustion engine. If the fuel is characterized by a higher than normal distillation point, the fixed volume of fuel may not be enough to generate the desired idle stability and acceleration due to undesired enleanment. Enleanment creates a feel that the motor vehicle is underpowered. Therefore, attempts have been made to compensate for the composition of the fuel supply to be combusted by the internal combustion engine.
One such attempt is disclosed in U.S. Pat. No. 5,229,946 which discloses a method for optimizing engine performance for internal combustion engines. This method accounts for different blends of fuel; namely, pure fuels and different blends of fuel and alcohol. This method utilizes specific engine parameters to determine what type of fuel is being combusted. This method utilizes a different engine map for each blend of fuel. This approach is not flexible in that it requires a specific blend of fuel before it can look up a value in a specific map. This method also relies on sensing the amount of fuel in a fuel tank to determine whether a sensing event should even occur.
The method disclosed in U.S. Pat. No. 5,229,946 fails to immediately determine the composition of the fuel to better enable the internal combustion engine to operate during demanded acceleration situations. In fact, this disclosed method does not identify the fuel composition until the fuel tank is refilled. Further, there is no provision to measure the performance of the internal combustion engine. The method merely estimates the performance based on the last identification of fuel composition.